/ K idioms.
/ derived from http://www.softwarepreservation.org/projects/apl/Papers/THEAPLIDIOMLIST
/ many idioms described already have K primitives or simple juxtapositions.
/ these are a few which caught my eye as non-obvious and useful and translate nicely to K.
(
{x>\:!|/x}[0 2 3 7 5 1] / (5.3) histogram
{x@&|\~" "=x} " some whitespace " / (5.5a) strip leading spaces
{x@&||\~" "=|x}" some whitespace " / (5.5b) strip trailing spaces
{x@&a|1_1!1,a:~" "=x}" a b c d " / (5.5c) compress repeated spaces
{&//x=+x}(1 2 3;2 3 2;3 2 1) / (6.6) is x a symmetric matrix?
|\0 1 1 0 1 0 0 / (7.5) right smear
+/&\1 1 1 0 1 0 0 1 0 / (14.1) index of leftmost 0
)